Parachuting



u 25, 1941- G. 'G. SERKAU 2,253,586

I PARACHUTING I Filed Aug. 14, 1940 4 Sheets-Sheet 1 INVENTOR, d'abn'el (1" il berlperkau It. LIA iZorney.

' Aug.'26, 1941 G. G. SERKAU PARAGHUTING Filed Aug. 14, 1940 4 Sheets-Sheet 2 Patented Aug. 26, 1941 aesassc PATENT oFFlcs rsnsonu'rma Gars Gilbert Serhu, Montreal, Quebec, Canassignor to F. William Zelcer, New Ifork,

Application August 14 1940, Serial No. 352,599

16 Glaims.

The subject of this invention isa novel and valuable method of and apparatus for use in training paraehutists, particularly the members of the aviation arms of military and naval iorces.

According to the present invention, the tyroparachutist is not only gradually familiarized.

, with the heart, blood-circulation, lungs and nerve reactions of one making a parachute descent from as high an altitude as desired (and this while dangling pendulum-like, as by beingheld in the usual parachute body-harness, from the lower ends of the shrouds pendent from the skirt of the parachute canopy or umbrella exactly as an aviator thus hangs after bailing out from a disabled airplane), but also is otherwise trained in accustoming himself to conditions actually likely to be encountered by an aviator in saving himself from a disabled airplane by parachute Jump.

During parachute descent by the present invention, the parachute umbrella is not restrained by the fixed and more or less vertical previously employed rods, cables or ropes, and hence its path of descent maybe an irregular one pursuant to varying wind currents at various points of descent, with sometimes a fluttering of dinerent parts of the umbrella, sometimes a spinning thereoi, and sometimes a sudden and even Jerky swinging of the parachute in some unanticipated vertical, lateral or other direction, and soon. According to thepresentinvention, the parachute umbrella in all parts thereof, and consequently the entire parachute is free to respond fully to any and all air currents; and so the present invention is based on aconcept which'is the very opposite of the conceptual foundation of previous proposals, all of which have held the parachute captive to a certain extent, during descent,

or during ascent preparatory to descent, or both.

The present invention provides" not merely the advantages iust indicated, but-others, some of which will now :be mentioned.

A feature of the invention is that the tyroparachutist, after he has been attached to the parachute, preferably by the ordinary harness as above, and this desirably after the umbrella of the parachute has been distended or spreadto operating condition by mere air-stream meansrather than by a mechanical spreader-frame built in or acting coadiuvantly of the. umbrella as heretofore, is not slowly and noisly elevated ated by a power-driven which. but, instead, is

sent aloft, to as great aheight as desired, and

swiftly, solely by a blast of upwardly directed air.

may thus carried out, and hence pursuant to the 7 now favored way of carrying out the method of the invention, this air-blast is delivered from a different air-stream source than that for distending or spreading the parachute umbrella preparatory to the air-operated ascent of the parachute which is to precede the descent thereof.

In the now favored way of carrying out the invention, also, another feature of the invention is that said air-blast is so upwardly directed against the undersideof the preparatorily pneumatically spread umbrella, and particularly so relative to the peak or crown thereof, that while the. parachute is elevated by air pressure and solely by air pressure, it is thus shot aloft not only along a path which extends at a selected ansle of inclination to the plane of the horizon, and at in azimuth, but withal at varying rates of speed precisely as predetermined, all for important purposes which will be explained below.

by agcable or the like wound on a drum op'er- It follows,therefore, that by the present invention the tyro-parachutist is subjected for the first time to aerial experiences which not only give him an unique preliminary training for actual parachute-jumping, practice later, but which in and by themselves aiford him novel and thrilling aerial-travel experiences as well.

Consequen y. the present invention, aside from the special advantases peculiar to it, has, like previously proposed methods and means of'training parachutists, the advantage of providing a development of military, value, and also one of great public appeal and hence of real utility in the amusement field; while entirely obviating the enormous cost of fabricating and erecting previously used structual-steel towers and like edifices rising to great heights. One such ediiice, at present prominently in use, and rising to a height of between zoo and 250 feet, requires v such heavy special footings and foundations and such a multiplicity of structural-steel units, not to mention other complexities and cost-increasing features, or the high operating labor overhead due to the need for ground crews of many men, that, aside from the initial large expenditure required for the making and building upl'of its component parts, and aside from the expense of transporting theseparts from one location to another, the mere cost of re-erection on a new site is commonly rumored to be in the neighborhood of $50,000. Thus, in' the aviation training field, it ishardiyfeasiblereadilytotake down the edifice at one location, transfer it to another,

be prohibitive.

A distinct advantage of the present invention, in the regards just noted, is the comparatively trifling cost of fabrication of the apparatus, its

ready transportability, and the insignificant expense of setting it up at a new location.

Other objects and advantages of the invention will become clear or be pointed out in the course of the following description of a form of apparatus now favored for facilitating a carrying out of a now preferred method according to the invention.

This apparatus, in illustration of the invention as practiced according to present preferences, and not in any way in and of itself to be taken as delimitative of the scope of protection contemplated herein as defined by the appended claims, is shown in the accompanying drawings.

In these drawings:

Fig. 1 is a view in perspective illustrating said apparatus in an embodiment thereof now favored.

Fig. 2 is a transverse vertical section, taken on the line 2--2 of Fig. 1.

Fig. 3 is an elevational view of said embodiment, the same being shown on a reduced scale--this view also showing the parachute with its umbrella spread by upwardly directed airstream and with the parachute floating with a slight upward pull against its tethering by engagement of its shrouds-carried snap-hook with a temporary anchorage therefor.

Fig. 4 is a view similar to Fig. 3, but showing the tyro-parachutist connected to the parachute for being borne aloft, said snap-hook having been disconnected from said anchorage and connected to the body harness worn by him.

Fig. 5 is also a view similar to Fig. 3, but showing the parachute with the tyro-parachutist carried thereby starting its ascent.

through the upper or nozzle end of the taller standpipe, and illustrating a means for varying the internal wall of such nozzle to modify the air blast delivered therefrom.

Fig. 12 is a top plan view of said nozzle and means.

Fig. 13 is a horizontal section, taken on the lines |3-I3 of Fig. 11.

Fig. 14 is, to the left of the line Ila, a top plan view of a handwheel for manually operating said means and a ratchet forming part of an automatic control for said'means (this showing being a horizontal section taken substantially on the line H-Il of Fig. 11); and, to the right of said line Ila, a side elevational view of an engine shaft equipped with a speed-responsive means forming, with electrical means more or less diagrammatically shown, other parts of said automatic control.

'In explaining the invention by reference to these drawings, the structural features of the apparatus thus illustrated will first be described with some allusions to function, and then the now favored way of carrying out the method of the invention by the use of said apparatus will be 7 explained.

However, by way of preliminary, the method Fig. 6' is an enlarged detail view in vertical section, showing certain of the parts seen in Fig. 2, and as there seem-but showing the taller airstream-delivering standpipe in axial section and illustrating a modification relative to such standpipe as shown in Fig. 2 in that the standpipe is served by a sle'eving means for acting as a cushion-buffer for apurpose later explained.

Fig. 7 is a view similar to Fig. 6, but illustrating a modification so far as the air-source means for said standpipe is concerned.

Fig. 8 is also a view similar to Fig. 6, but showing another modification of said air-source means.

Fig. 9 is a view similar to that part of Fig. 6 illustrating the said standpipe and its variableangle or aimable securement to the ascentplatform, but showing a modification of such aiming means.

Fig. 10 is a vertical section, taken through the ascent-platform, showing a modified form of such platform, and a further modified aiming'means for said taller standpipe the use of which is facilitated by said modified form of platform.

Fig. 11 is a view, principally in axial section directing against the underside of the parachute umbrella a stream of upwardly directed air of a velocity and spread adapted to distend the umbrella to substantially its normal extent of substantially unrumed upward bellying-spread when descending with a parachutist suspended therefrom and alsoto cause the parachute to have somewhat of a tendency to float upward against a point of tethering thereof. This step is performed either while the parachute is thus tethered to the body of the tyro-parachutlst, hereinafter called the parachutist, so that such point is in proper suspensory relation to the 7 center of weight of his body, as by making such point correspond with the usual eye on the ordinary parachutists body-harness worn by him which takes the snap-hook commonly .connected to the lower ends of the shroud-lines or shrouds pendent from the skirt of the parachute umbrella; or while the parachute is temporarily tethered to an inanimate anchorage as mentioned above in briefly describing Fig. 3. In the latter case, the second step would be to connect the shrouds. as by said snap-hook, to the parachutist, that is to suitable body-harness donned by him.

The next step, although as below explained preferably carried out in such manner as to have different sequentially performed phases or stages, involves the direction against the underside of the parachute umbrella of a stronger stream of upwardly directed air and one. of a velocity and spread (this last in the sense of minimum rather 4 than maximum spread) such as to raise the umbrella to a height of the order of to 250 feet or more.

A preferred corollary of this step is as store.-

said to aim the standpipe or the like used for stronger air stream is thus accommodated to the just begins to overcome momentum. will be so nicely controlled that the parachute may be depended on todescend in such manner that the parachutist will come down to the ground somewhere within a comparatively small area, as one of the Order of 100 square feet. Actual tests have shown that if said standpipe is properly aimed as above, in the direction of the wind but against the wind, the parachutist can be depended on to land within an area as small as that just above indicated.

The final step. performed when the air-blast ascent of the parachute has been performed to the prevised height, or rather, to a height suchthatwhen the necessarily performed addendum due to momentum is completed, the parachute will have ascended to the predated height,

is the step of sumciently relieving'the upward pressure of the air-stream from said standpipe or the like, preferably by shutting off said airstream, to allow the parachute to descend with the parachutist borne thereby at about the usual speedof descent of a parachute of the same diameter, after bailing out from'an airplane and following opening of the umbrella consequent upon pulling the rip-cord.

As to the step hereinafter briefly touched on as preferably carried out in such manner as to have different sequentially performed stages, this,

' it is now believed, is best performed by first lifting the parachute by the air-stream now bein discussed, and with said'strearn of comparatively small velocity, to a certain height rather considerably less than the maximum prevised height of ascent (so that duringthis iirst ascent the parachute will be-elevated relatively slowly) by then rather suddenly and very greatly increasing the velocity of said air-stream, thereby to deliver a somewhat abruptly delivered yet somewhat sustained blow to the undersideof the umbrella,

shown as at 2|, above ground level, and with the platform carried by corner pillars 22, and reached by a flight of steps 23.

An idea of the relative dimensions of the elements shown, these including the taller standpipe aforesaid, the same marked 24, a shorter standpipe ii for discharging the air-stream of lesser velocity for raising and spreading the canopy 26 of the parachute to transform the parachute from the condition shown in Fig. 2 to that shown in Fig. 3, and a temporary anchorage 21 for the snap hook 28 connected to the lower ends of the shrouds 29 of the parachute-so far 'as the illustrated and preferred apparatus is concerned-will be had if it is pointed out that as shown the platform ii is about eight feet.

square, the standpipe 24 is about nine feet high above the upper surface of the platform. the' standpipe is about three feet high, and the anchorage 2'! isabout twof'feet high along its top horizontal bar 21a which with its two depending, legs 21b provides a simple and light structure of inverted-U shape.

that is, a pneumatic drive against the underside .ofthe umbrella of a kind to shoot the parachute upward at relatively high speed: and by then rather suddenly cutting down largely, or cutting oficompletely, said air-stream, thereby to have the parachute complete its rise to the. predetermined maximum height of ascent solely or sub? stantialiy solely by momentum. Referring now in detail-to the apparatus in the drawin and more particularly to 1 and 2: Y

At II is shown an ascent platform constituting the roof of a chamber within which is housed the means for providing the two air-stream sources preferably employed. One, such means shown is an airplane motor ll driving a suitable airplane propeller ll of the two or even three or four This structure is, like the rest of the apparatus, very inexpensive to make; being built up of ordinary steam-fitters pipe as shown and. the usual elbows and nipples as indicated-said nipplea,- marked 21c, providingannular stops for limiting casual shift of the snap-hook materially away from the center of the bar 2111 following engagement of said hook with the bar between the nipples 21c. I

The tank i8 is provided with a safety valve 30, to prevent the air pressure therein exceeding a predetermined maximum; and leading from the top of the tank is a conduit 3| connected to the lower end of the standpipe 25, said conduit having interposed therein a manual valve 32 openable to cause an air-stream of lesser velocity to issue from the top of the standplpe 25, and closable to shut off this air-stream.

The airplane motor I6 is desirably one of the rotary type, but it could be, as indicated, a-regular eight to twelve cylinder straight-in-line mofor: of about 100 H. P., and havinga speed in the neighborhood of from about 1200 to 1500 R. P. M. The'c'ooling system of the motor is not shown;

continue for more than about fifteen seconds.

water-cooling would usually, at practically any site, be recommended over air cooling; as the latter would involve, preferably, the provision of a sirocco fan or the like and a power-unit for whirling the same, to-deliver over the motor an air flow of a velocity of the order of the relative wind in flight were the motor the power-plant of an airplane. While actual experiments have not been as yet made in this direction, a watervane type, such as used in wind tunnels, with. i

the vanes of substantially constant width from root to tip and having an attack angle or pitch of approximately 45, and the other such means an auxiliary pressure tank II for storing compressed air at the pressure desired and served by an electric-motor driven compressor II by way of a duct 2| between the compressor and the said chamber would in many cases desirably be an excavated pit, with the platform at cooled marine engine of about 3,000 B. P. M. has,- so far as the cooling problem is concerned, especially when the apparatus-is used to raise the parachute to a height of say 300 feet or over by positive air pressure against the underside of its umbrella, many attributes which would makeit theoretically ideal.

I'br leading the air from the propeller II to the lower end of the standpipe 24, a more or less funnel shaped collector and supply conduit 38 can be used, shaped as shown-in Figs. 1 and 2,

about ground level; but the chamber is here 76 but, where aelight increase in the height of the chamberll isof no moment, asis generally the The standpipe 24, however, in order to illus- V trate various features of the invention all now deemed of considerable importance, is shown as incorporating a special nozzle 34 at its top or discharge end; a means interiorly of the main length of the standpipe andhere shown as in the form of internal ribs or fixed vanes some of which, marked 35 in Fig. 6, are straight, and

. others of which, marked 38 in Fig. 6, are of helical or spiral extension; a means including in part a special section 3'! of the standpipe and in part a variable-length brace marked generally 38, for adjusting the axis of the nozzle and of the upper length of the standpipe to a selected angle of inclination to the plane of the horizon; and a means including a bevel bull-gear 39 fixed to the lower end of the standpipe just above the upper surface of the platform l5, for adjusting said axis to inclination in accord with a selected angle in azimuth.

The nozzle 34 is shaped interiorly like a Venturi tube for discharging an air blast of high velocity and restrained girth, so that the blast will be in the form of a high-reaching column of laterally compacted air of great load-bearing and load-lifting efficacy. Best results would seem to be obtained when said nozzle is about 12" long, about 1 in diameter at both top and bottom, and about 1%" in diameter at its waist or point of minimum internal cross-section, with this point about 9 above the bottom of the nozzle.

The ribs or vanes 35 and 36 inside the standpipe 24 could be all straight, as are the vanes 35, or all spiral or inclined, as are the vanes 36, but a combination of the two, as shown, would, it is now believed, give best results. The purpose of these vanes is to combat such rotatory disturbances of the air in the standpipe sufllcient materially to shorten the effective length of said air column as a blast as aforesaid after issuance from the top of the nozzle 34. The presence of the vanes 35 or 36 or equivalents is now believed to be of considerable importance, especially where plane of the horizontal, the section 31 of the standpipe 24 is made flexible, as by constructing the same of rubberized fabric as indicated. For holding the nozzle when adjusted to such inclination, the brace 38 is provided, said brace ineluding an upper rod and a lower rod joined by a turn-buckle as shown most clearly in Fig. 6. The upper end of the upper rod is shown as pivotally connected to acollar 38 fixed at a high point on the standpipe 24, and the lower end of the lower rod is shown as similarly connected to the bevel gear 39 as at 39'.

In order to aim the center-line of the nozzle 34 in agreement with a selected azimuth angle, when the nozzle is inclined as described in the paragraph preceding and so as then to place the I brace 38 so that its upward inclination and direction of thrust extends to windward to have it act as a strut rather than as a guy, the bevel gear 39, fixed as aforesaid to the standpipe 24,

is rotated. As shown best in Fig. 1, this rotathe compressed air delivered to the standpipe 24 is the wind from an air screw and such air screw is rotated not about a horizontal axis, as in Fig. '7, but about a vertical axis, as in Fig. 7 or Fig. 8

In these last-mentioned views, the platform I5 is shown, also the lower part of the standpipe 24, and, between the bottom of said standpipe and the air screw, marked ll, an inverted funnel 33". In Fig. 8, the engine for driving this screw is indicated at l6, and it will be noted that this engine is of the upright type having a vertical shaft on which the screw I1 is secured. The arrangement of Fig. 8 is a very simple one,

but, in view of possible lubrication dimculties,

the arrangement of Fig. 7 is now preferred over that of Fig. 8 where it is desired to have the air screw on a vertical shaft and at the same time to have the engine shaft horizontal; which end is attained by providing the bevel-gear drive shown in Fig. '7.

In order to permit inclination of the centerline of the nozzle 34 at a selected angle to the tion can be done by means of a bevel pinion 40 fixed on a shaft 4| suitably journalled at 42 and 43 and carrying-a handle 44.

The standpipe 24 is preferably provided with a buifer cushion so that no sudden gust of wind, as the parachute is in the early stages of its ascent, can possibly injure the parachutist by slammingly swinging his body against the standpipe. Such a protective feature is illustrated in Fig. 6 as including an inflatable bag 45 of rubber or the like, with such bag having a textilefabric casing or lining (not shown) to hold it more or less to a predetermined contour of distension or inflation. Inflation air for this-bag is supplied by a line of piping 46 leading from the auxiliary pressure tank l8 and having interposed therein a valve 41. I

This valve is a three-way'one, so that in one setting thereof the bag 45 may be deflated by connecting its interior with the atmosphere.

A safety valve is indicated at 48, to prevent inadvertent subjection of the interior of the bag to too high an air pressure.

Referring to Fig. 9, this illustrates a standpipe, marked 24a, in all respects similar to the standpipe 24 of Figs. 1 and 6, except that the flexible section 31 of the latter standpipe is omitted, and the standpipe is rigid from top to bottom.

The standpipe 24a of Fig. 9, however, at its lower end, has fixed thereon a semi-globular member 49 and has threadedly adjustable thereto the standpipe 24a by a handwheel 50 forming here an integral portion of the ball-and-socket joint member 50. Thus by way of this handwheel, said member 50 may be turned in one direction, to loosen the joint for inclining the axis of the nozzle 34 at a. selected angle in azimuth and at a selected angle to the plane of the hori- 2011; or turned in the reverse direction to tighten the joint to lock the standpipe as so adjusted. A collar 54 is shown as encircling the upper end of the nozzle, and as having an apertured ear 55 offset therefrom, and is adapted to be engaged .to a minimum diameter.

by a pull rod hook to facilitate inclining the standpipe as desired.

Referring to Fig. 10, this shows an arrangement whereby, with the standpipe 24 rising above the platform 18, the lower end of such standpipe, a funnel 83a, an air screw "a and an engine I80 for rotating said screw, are all moved in unison to vary the inclination of thenozzle at the upper end of the standpipe as desired. Here the engine, for simplifying the drawing shown as having its shaft vertical, has rigidly mounted thereon the funnel 83a, and the latter has rigidly mounted thereon the standpipe 24. Between its top and bottom the engine is provided with a pair of trunnions one of which is shown at 58; these trunnions being Journalled on standards rising from a baseplate 58. The bottom of the engine carries a worm-gear 58 having a depending annular flange or skirt resting on a circumferential line of balls 88 in a race 8i carried on the upper side of a disk 82 including therebelow, and diametrally thereof, a worm-gearsegment 82. The teeth of the segment 82 mesh with a worm 63 fixed on a shaft 64 provided with a' handle 65. The teeth of the worm-gear 59 mesh with a worm 88 fixed on a shaft provided with a handle 68. Turning of the handle 65 inclines the center-line of the nozzle at'the top of standpipe 24 to a desired angle to the plane of the tion thereof is provided with a flexible section 10, as one of rubberized fabric, whereby said section can be variously restricted relative to its zone of minimum diameter. As. such diameter is more and more restricted, the Venturi action .of the nozzle is increased; asmight be desirable where the parachutist weighs say 200 lbs. or otherwise has a weight considerably over the normal average of 160 lbs. for an adult male.

The means forthus modifying the action of the nozzle 89 includes a ring Ii welded or otherwise suitably secured around the upper mouth of the nozzle, and having spaced therearound a meshing with a bevel pinion II on asomewhat inclined but mainly vertically disposed shaft 80 suitably Journalled by means not shown and having fixed thereon a handwheel 8|.

A means operable when desired, for automatically varying the Vcnturi action of thenozzle 88, by rotation of the shaft 88, is also shown, in Figs. 13 and 14, as follows; 1 Fixedon shaft 88 is a ratchet 82, with which is engaged a. pawl 88 on an arm 84 loose on the shaft. A holding pawl 85 is also shown, this pivoted on an extension 88 rigidly carried .by a fixed support 81. With these pawls as in Fig. 13, said automatic means is operative; while to disconnect-the latter, for manual adjustment of the Venturi action of the nozzle 69, by way of the handwheel 8i, hooks 90 are carried by suitable fixed supports not shown so that the bills of these hooks can be engaged with the illustrated apertures in the two pawls 83 and 85 and so hold them away from the ratchet 82.

As here shown, the actuating means for stepby-step advance of the ratchet 82, thereby more and more to constrict the waist of the section 10 of the nozzle 89, comprises an extension 84' of the arm 84, to the free end of which extension is attached a link connection for the armature of a solenoid 9|, whereby on each energization and subsequent deenergization of said solenoid the pawl 83 is operated to turn the shaft 80 through the extent'of one tooth of the ratchet 82; a centrifugal-sp'eed-governor type of device $2 on the. shaft 83 (of the enginefor driving an airplane propeller or air-screw; these parts not shown),

one ball or weight. 84 of which device carries a wiper-contact 85 adapted, as said engine is speedseries of radially arranged cradle-like hangers i2;

and a corresponding number of pendent and radially swingable constrictors 13 each having at its top. an outwardly and downwardly extended hook 14 for rocking-suspensiveinterlock with the cradle of a hanger 12, each having at itslower outer face a colunm of thread-elements 15, these thread-elements of the different const'rictors combining to form a mutilated male thread, and

' each'having an intermediate. portion bulged in toward the exterior of the section I and laterally of its inner face concavely curved as indicated at I8 in Fig. 11, such curvature being to a radius the same as that of the exterior of the waist portion of thesection I! when constricted Venturi action of the nozzle carries a bevel gear 18,

adjustment of the collar 11,

ed up more and more, to snap into engagement with, and then away from, each of a line of contacts $6 spaced along an arcuate line and carried by a support 98 of insulating material as indicated,'seriatim, as the contact 94 moves through a corresponding arcuate path. The device 12 carrying the last-named contact is insulated from the engine shaft 92 by an insulator-ring B1, and ismaintained in circuit with the other contacts by a collector-ring 9t and a fixed brush 99 engaging the same. As will be made clear from the subioined description of the now preferred way of carrying out the method of the invention, the parachute is to be rather abruptly catapulted upward after it has been comparatively slowly and gently raised to elevate the parachutist to a safe height above the top of the standpipe 2401' equivalent; and

for this catapulting the air blast from the top of said standpipe should have a sudden and very ment .the velocity and lift-power of said air blast, beyond a point possible from merely sud-. denly racing the engine, that means such as 11- lustratively shown in Figs. 11 through 14 is desirably present. As will be now understood, in

that very brief interval of time during which the engine is sent from idling to racing speed,

the Venturi action of the nozzle 89 is more and more increased, due to rapidly occurring successive energizations of the solenoid 8|.

The method of the invention, briefly to sum up such method as'now preferred, is as follows: a

(a) The first step, as aforesaid, is, after the parachute is arranged as in Fig. 2 relative to the standpipe 25, to raise the parachute and spread its umbrella. Hill, to the end that the parachute is. elevated and upwardly floating above the platform IS with just about enough ascension tendency substantially to tauten its shrouds. This step can be performed before attaching the snap-hook 28 to the harness IM of the parachutist, as shown in Fig. 3, and with said hook thereafter to be connected to said harness, as shown in Fig. 4; or after connecting said hook to said harness. The air stream sent from the standpipe 25 for first thus distending and raising the umbrella I will depend on the diameter of the aperture at the top of said standpipe, the weight of the parachutist, and the velocity and direction of the wind; but it can be as low in pressure as that equivalent to the force of a ten-mile breeze, when a mild wind is blowing, and the weight of the parachutist is in the neighborhood of 150 to 1'75 lbs.

(b) The next step is to take care of what may 7 be'called the ante-catapult stage of the ascension.

Y speed, and then by gradually occurring but fairly slight increases of speed until the parachutist is at an altitude of about 25 feet above'the platform l5.

havior of a parachute with a human parachutist (c) The next step is the discharge of such a I strong air blast from the standpipe 24 as to.

deliver a sudden and rather abrupt pneumatic catapult the parachute quickly to a height within 25 to 75 feet of the maximum prevised height of ascent thereof, that is, to within about 25% of the total of such height.

(d) The next step is to shut oil or otherwise sufliciently diminish or relieve the air flow from the standpipe 2! to accomplish the aim of allowing the parachute actually or in effect to complete the remainder of its prevised ascent, by momentum.

Where a deal calm is prevailing, the operation of the method would not include a preliminary step, or first-step proper, for the purpose of aiming the center-line of the air-blast to be delivered from the standpipe 2| so to windward as to prepare in advance for the wind then prevailing to cause the parachute to descend along a path to land the parachutist very close to his point of ascent, as already explained. But, if a wind-is blowing, this preliminary step is desirably performed, by preparatorily properly laying the standpipe 24 in range and in azimuth. Preferred shown in Fig. 2 to that shown in Fig. 3 and up to the point where the underside of the umbrella i II is subjected to the air stream from the standpipe 2|.

It has been explained how by the present invention the parachutist may be so sent aloft that on the ensuing descent of the parachute he may be depended on to land very close to his point of ascent: so that he cannot be injured by landing at an unanticipated point on the water or in rough terrain. He is further to protected against any chance of injury, it is recommended, by making the umbrella about 32 feet or more in diameter, rather than the usual 24 feet; as then, when he 'lands, his body will sustain, not

about the shock to be expected following a Jump down from a ten-foot high wall, as usual, but only about the shock to be expected following a jump down from a fairly low table.

As will be understood, variations and modifications, other than those hereinabove indicated, are possible within the scope of the invention, and parts of the improvements can be used without others.

-I claim: I

l. The method of controlling the aerial. be-

carried thereby, for training and amusement pur-' poses, which involves acting on the parachute with its umbrella uppermost but in gravity-collapsed droop, to effect the physical change in the umbrella of transforming it from such drooped condition to a spread condition, by directing against the underside of the umbrellas stream of upwardly directed air of a velocity and spread to distend the umbrella to substantially its normal spread when descending with a parachutist suspended therefrom, while restraining the parachute, by way of the lower ends 'of the shrouds thereof, against tendency toward ascent greater than substantially to tauten its shrouds against the weight of a parachutist harnessed to the latter adjacent to their lower ends, by holding said velocity down to only about that required thus to tauten the shrouds and hence one less than would be required to lift the parachute with the latter weighed down by the parachutist; then. while the parachute is thus weighed down and restrained against further ascent solelyv by the weight of a parachutistg thus harnessed thereto, directing against the underside of the umbrella a stronger stream of upwardly directed air and one of. a .velocity and spread such as to raise the umbrella of the parachute to a height abovethe previous height of the umbrella equal to at least several times the diameter of the umbrella when spread; and then sumciently relieving the underside of the umbrela from the upward pressure with its umbrella uppermost but in gravity-collapsed droop, to eflect the physical change in the umbrella of transforming it from such drooped condition to a spread condition, by directing against the underside of the umbrella a stream of upwardly directed air of a velocity and spread to distend the umbrella to substantially its normal spreadwhen descending with a parachutist, while restraining the parachute. by way of the lower ends of shrouds thereof, against tendency toward ascent greater than substantially to tauten said shrouds, by holding said velocity down-to only about that required thus to tauten the shrouds and hence one less than would be 'required to lift the parachute with th latter weighed down by the parachutist; then harnessing the parachutist to the shrouds adjacent to 7 their lower ends: then directing against the ununderside of the umbrella a stronger stream of upwardly directed air and one of a velocity and spread such as to raise said umbrella to a height I above its previous height equal to at least several ward direction so far as the horizontal comtimes its diameter when spread; and then sufliciently relieving the underside of the umbrella from the upward pressure of the last-named stream of air to allow the parachute to descend with the parachutist 3. A method as in claim 1, in which the firstnamed air stream is delivered from a reservoir or supply tank of compressed air, while the second-named airstream is delivered from another source of air supply than said tank and as developed at said source.

4. A method as in claim 1, in which the secondnamed air stream is discharged as developed by an airplane propeller driven by an engine and the wind thereby created is guided and converged toward a predetermined port, and is thenconfined and guided above said port to a higher point, and in which said engine is sooperated,

by running the same at one speed, that the first action of said air stream against the parachute umbrella is a comparatively slow'and gentle one to raise the parachute to a height representing a lesser part of the predetermined maximum height of ascent thereof, and then so operated,

by rather suddenly considerably increasing the speed of the engine, that action of said air stream against the umbrella is so relatively. abrupt and powerful that the eifect on .the umbrella is that 01' apneumatic shot thereby as it were to catapult the parachute to a height at least more than twice the height attainedby the umbrella before the beginning of such catapulting action.

5. A method as in claim 1, in which the secondnamed air stream is first discharged at a velocity suilicient to raise the parachute comparatively slowly and to a height representing the lesser part of its predetermined maximum height of ascent, in which said air stream is next discharged at a greater velocity to cause relatively rapid further ascent of the parachute and to send it to a height representing the major part of said maximum heightand in which next the upward pressure from said air stream is sumciently relieved to permit momentum to carry the parachute to said maximum height.

ponent of its path of descent is concerned.

7. Apparatus as and for the purposes described,

' including, in combination, a first standpipe .for

delivering upward an air stream of lesser velocity;

.means' serving said first standpipe for supplying air under pressure for such stream; a second standpipe for delivering upward an air stream of greater velocity; means serving said second standpipe for supplying air under pressur for. such stream; a platform adjacent to and below a the tops of said standpipes for a person harnessed to the parachute, the first standpipe being of a height such that the crown of the parachute tially tauten its shrouds, the second standpipe being of a height considerably greater than the height of the first standpipe; and cushion buffer means for encasing said second standpipe protecf tively relative to said person when the parachute with said person suspended therefrom adjacent to the lower'ends of its shrouds is raised to elevate said person to a point above the top of the v second standpipe, the means serving said second standpipe as aforesaid being adapted to supply the latter with air under such pressure as to cause discharge of the air stream from the second standpipe with great enough velocity to raise the parachute to elevate said person to said point.

8. In outdoor apparatus of the class explained, the combination of a means for discharging an upward blast of air against the underside of the j umbrella of a parachute while the umbrella is .spread and elevated but restrained against a 6. The method of controlling the aerial behavior of a passenger carrying parachute, which spread condition, by directing against the u derside of the umbrella a stream of upwardly directed air of a velocity and spread to distend the umbrella to substantially its normal spread when descending with such passenger while slightly raising the same; sufliciently prolonging said action to maintain the umbrella thus distended and raised while restraining the parachute against tendency toward ascent greater than substantially to tauten its shrouds against the weight of said passenger, such weight being the means of exercising such restraint; and directing against the underside of the umbrella as thus distended and raised a stronger stream or upwardly directed air and one of a velocity and spread such as to raise the umbrella to a height above the previous height of the umbrella equal to several times its diameter when spread, and one predetermin'edly inclined relative to the direction and velocity. of

the then prevailing wind; such that on suiiicientchute to descend such descend will be in a windgreater tendency to rise than sufficient substantially to tauten its shrouds, said means including an upstanding conduit having near its upper end a discharge orifice for said blast; means for supplying air under pressure to said conduit to es tablish said blast; and means for vary ng the direction of discharge of said blast from said orifice to have said direction agree with a selected azimuth angle and also with a selected angle to the plane of the horizon.

9. In apparatus of the class explained, the combination or a means for discharging an upward blast of air against the underside of the umbrella of a parachute while the umbrella is spread and elevated but restrained against a greater tendency to rise than suflicient substantially to tauten its shrouds, said means including a conduit having a discharge orifice for said blast; and means operative to supply air under pressure to said conduit to establish said blast, said supply means including means for delivering air to it,

said delivering means including anair-screw and a power means for rotating the latter and means for directing the wind trom'said air-screw to said supply means.

iol In outdoor aparatus of the kind discussed, the combination of a platform; a shorter standpipe adjacent thereto; a taller standpipe also adjacent to said platform; an anchorage tor the snap-hook-of a parachute; an air reservoir; a

valved conduit connecting said reservoir and said shorter standpipe; air compressing means serving said reservoir; an air-screw; a power-means for operating said air-screw; means for controlling the operation '01 said power-means to vary the wind developed by saidair-screw; and means for flexible and a section thereabove leading to a discharge orifice for said wind, and in which a means is provided for holding said standpipe with the first-named section flexed to an extent to cause said orifice to discharge an air blast so aimed as to have a line of discharge at a selected angle to the plane of the horizon and also at a selected angle in azimuth. I

13. In outdoor apparatus of the kind explained, the combination of a means for discharging an upwardly directed air blast of suflicient velocity to catapult upwardly in a windward direction a parachute by acting against the underside of its umbrella; a means for preparatorily spreading and elevating saidnmbrella to maintain the same elevatedto an extent substantially to tauten'its pendent shrouds against the weight of a person harnessed thereto: and a means for adjusting the means first-named to direct said blast at a predetermined angle to the direction of the then prevailing wind.

14. An apparatus as in claim 13, in which there is also a means for adjusting the means first-named to direct said blast at an angle to the plane oi. the horizon having a less or "greater inclination to said plane according as the velocity of said wind is less or greater.

15. An apparatus as in claim 13, in which, in combination with said discharging means, there is a means for supplying the latter with air under pressure, and there is also a means, operative adjacent to the discharge point of said blast, for

, vary the velocity 01' the blast.

GABRIEL GILBERT SERKAU. 

